An electrically powered, ring-shaped radiant heating element is maintained at a temperature of Th = 3000 K and is used in a manufacturing process to heat a small part having a surface area of Ap = 0.007 m2. The surface of the heating element may be assumed to be black. For ?1 = 30°, ?2 = 60°, L = 3 m, and W = 30mm, what is the rate at which radiant energy emitted by the heater is incident on the part?
